Fire bridge, especially for transportable furnace plants



Feb. a u. BARSKE 2 FIRE BRIDGE BSPBCiALLY FOR TRANSPORTABLB FURNACE PLANTS Filed bec'. 12. 1929 Patented Feb. 17, 1931 UNITED STATES PATENT OFFICE ULRICH BARSKE, OF HANOVER-RICKLINGEN, GERMANY, ASSIGNOR TO THE COMPANY HANNOVERSCHE MASCHINENBAU-AC'IIEN-GESELLSCHAFT VORMALS GEORG EGE- STORFF (HANOMAG), GERMANY FIRE BRIDGE, ESPECIALLY FOR- TRANSPORTABLE FURNACE PLANTS Application filed December 12, 1929, Serial N0. 413,660, and in Germany July 30, 1928.

It is known for locomotive firings to form the fire bridge of water cooled elements, which consist either of hollow plates or of telescoped or simple tubes. In the arrangement last mentioned the tubes, rising vertically from the base of the fire bridge and arranged close together, are obliquely bent at the upper end and then oin again to the boilor circulation in lateral bends. All these constructions are ope-n to the objection, that the specially shaped tubes, which are expeir sive to produce, are not easily accessible for cleaning, which particularly applies to the last mentioned fire bridge formed only of. water tubes, asin this'case the tubes are bent in the most various planes. v

The invention has for its object, to construct a fire bridge of tubes, which avoids the disadvantages above mentioned. The fire bridge according to the invention difi'ers from the known construction in that the straight rearwardly directed ends of the tubes rising from the base of the fire bridge, arranged close together and curved in the longitudinal axis of the fire box, bridging the rear part of the grate, are made in such a cross section, that at this point gapsfor the passage of the heating gases are produced between the tubes, forming passages for the flue gases. Consequently the individual tubes, in spite of the partial deformation of their cross-section, only constitute a simply bent tube, which is therefore easy to make and easy to clean.

An embodiment of the invention is illus trated by way of example in the accompanying drawing in which:

Fig. 1 showsdiagrammatically a locomotive firing fitted with the new fire bridge.

Fig. 2 is a cross-section in line 2--2 of Fig. 1.

The tubes 1 situated close together, forming the fire bridge, rise vertically from the lower end of the fire box and are curved in the longitudinal axis of the fire box over the front part of the grate. They then extend in a straight line through the rear wall of the firebox, where they are connected wlth the boiler circulation by means of tubes 3. The portion 2 of the tube extending from the funnel-shaped reduced portion a to the rear wall of the fire box is so shaped by narrowing of the cross-section that between the individual tubes gaps 5 are formed as passage-s for the fine gases.

The fire bridge according to the invention, which has a large surface for heat transmission, can be used without any alteration for high pressure purposes.

An important feature of the invention consists in that the lower portions of the tubes form together a solid wall, whereas their extended portions form passages for the flue gases. It is immaterial, whether these passages are formed by a'reduced diameter, altered cross-section shapes of the tubes, or by arranging the tube ends on different planes.

I claim l. A fire bridge for locomotiveand other transportable boiler firings, comprising a screen of water cooled tubes, arranged-close together, curved in the longitudinal axis of the fire box bridging the rear part of the grate and having straight rear ends extending towards the rear wall of the fire box and shaped so that gaps as passages for the flue gases are formed between said straight rear ends of the tubes.

2. A fire bridge for locomotives and other transportable boiler firings, comprising group of water cooled tubes arranged in close relation, said tubes being curved in the longitudinal axis of the fire box, bridging the rear part of the grate and having straight rear ends extending toward the rear wall of the fire box, and said straight rear ends being of reduced diameters relative to the curved portions of the tubes to provide intervening spaces for the passage of flue gases.

In testimony whereof I atfix my signature.

ULRICH BARSKE. 

